Biodegradable polymer microspheres and preparation method therefor

Abstract

Provided in the present invention are biodegradable polymer microspheres and a preparation method therefor. The preparation method comprises the step of polymerizing a biodegradable polymeric monomer in a mixed solution containing the biodegradable polymeric monomer, a water-soluble polymer and a catalyst. In the present invention, the monomer and the water-soluble polymer are mixed into a solution, and phase separation occurs, after the in situ polymerization of the monomer, to obtain the biodegradable polymer microspheres; the production process is simple and easy to control, without the need for an organic solvent; and the production process is environmentally friendly and the method is suitable for large-scale production.

1 - 5 . (canceled) 
     
     
         6 . A method for preparing a biodegradable polymer microsphere, wherein the method comprises a step of polymerizing a biodegradable polymeric monomer in a mixed solution comprising the biodegradable polymeric monomer, a water-soluble polymer, and a catalyst. 
     
     
         7 . The method of  claim 6 , wherein the biodegradable polymeric monomer is selected from a monomer of an aliphatic polyester. 
     
     
         8 . The method of  claim 6 , wherein the water-soluble polymer is selected from one or more of polyoxyethylene-polyoxypropylene ether block copolymer, polyacrylamide, polyvinylpyrrolidone, polyethylene glycol, polypropylene glycol, poly(vinyl alcohol), poly(acrylic acid), poly(methacrylic acid) and methyl cellulose; and/or in the mixed solution, the mass ratio of the biodegradable polymeric monomer to the water-soluble polymer is 100:(20-300). 
     
     
         9 . The method of  claim 6 , wherein
 the catalyst is selected from a metal, a Lewis acid, a Lewis base, an organometallic compound and a metal salt; and/or   in the mixed solution, the mass ratio of the biodegradable polymeric monomer to the catalyst is 100:(0.1-2).   
     
     
         10 . The method of  claim 6 , wherein the mixed solution further comprises an antioxidant and/or a functional material. 
     
     
         11 . The method of  claim 6 , wherein the reaction temperature of polymerization is 90-180° C. 
     
     
         12 . The method of  claim 6 , wherein the method comprises the following steps:
 S1. preparing a liquid monomer: taking a biodegradable polymeric monomer that is in liquid form at ordinary temperature for later use; or heating and melting a biodegradable polymeric monomer that is in solid form at ordinary temperature to obtain a liquid monomer;   S2. preparing the mixed solution: adding the water-soluble polymer into the liquid monomer, and completely dissolving the water-soluble polymer into the liquid monomer to obtain the mixed solution;   S3. polymerization: adding the catalyst into the mixed solution, letting the solution stand at reaction temperature to promote polymerization of the monomer, and obtaining a mixture of the biodegradable polymer microsphere and the water-soluble polymer;   S4. post-treatment: post-treating the mixture to obtain the biodegradable polymer microsphere.   
     
     
         13 . The method of  claim 6 , wherein the biodegradable polymeric monomer is selected from one or more of aliphatic lactides and aliphatic lactones. 
     
     
         14 . The method of  claim 6 , wherein the biodegradable polymeric monomer is selected from one or more of lactide, caprolactone, and glycolide. 
     
     
         15 . The method of  claim 6 , wherein the catalyst is selected from one or more of Fe, Cu, Zn, Co, an alkali metal salt, a Schiff base, dibutyl magnesium, an aluminum alkoxide, Ti[OCH (CH 3 ) 2 ] 4 , Sn(Oct) 2 , SnCl 4 , Sn(C 6 H 5 ) 4 , Sn(Oct) 2 /CH 3 (CH 2 ) 11 OH and Sn(Oct) 2 /P(C 6 H 5 ) 3 .